Strange size subwoofer (h:120cm,d:105cm,w:35cm)

[mvennik]

I am planning to build this subwoofer:



I have done the calculations with WIN-ISD and will use
2 Dynaudio 30W54 with the following TS-parameters:
Vas 257 Liter
Qts 0,3572
Qes 0,42
Qms 2,39
Fs 22 Hz
Sensitivity 90dB
Max Power 210 W
xmax 3,5 mm
Moving mass 45,61 g
Disp area 0,04 m2
Re 6,3 ohm

Does anybody want to comment on this, since I'm quite new in this game?

[JakeDN]

I might be totally wrong, but id say not to make it an oblong. You might get standing waves form inside. You'd want a sloping back or something like that. Also, might it not look better if you have one driver at the top, one at the bottom, and the ports in the middle?

[Thawach]

hi mvennik


i surprise that your home is very big like the church. u can use a very big subwoofer! if u do nok like a very big subwoofer. u can change the volume again. about 300-320 litre it increase about 1 db(for super rock concert)

You might get standing waves form inside

JakeDN! it may be changed when the box is bracing inside.

[nunayafb]

As I think Thawach was trying to say, if you design your brace accordingly you can stop the standing waves. I would use a single brace as poorly shown in the attached pic and experiment with stuffing to fine tune the sound.

[MaVo]

The lowest standing wave in it will be at about 140hz, between bottom an top end. Crossover well below that and you can ignore the standing waves. Also, making odd shapes doesnt really help against standing waves. It is done to please the customers eye.


Second thought... this is a bassreflex? With 7cm big ports? I think port noises of the air flowing through them could become a problem at higher levels of deep bass. But thats a guess. Generally, try to make ports long and with high crossectional area.